/*
** $Id: lctype.h $
** 'ctype' functions for Lua
** See Copyright Notice in lua.h
*/

#ifndef lctype_h
#define lctype_h

#include "lua.h"

/*
** WARNING: the functions defined here do not necessarily correspond
** to the similar functions in the standard C ctype.h. They are
** optimized for the specific needs of Lua.
*/

#if !defined(LUA_USE_CTYPE)

#if 'A' == 65 && '0' == 48
/* ASCII case: can use its own tables; faster and fixed */
#define LUA_USE_CTYPE 0
#else
/* must use standard C ctype */
#define LUA_USE_CTYPE 1
#endif

#endif

#if !LUA_USE_CTYPE /* { */

#include <limits.h>

#include "llimits.h"

#define ALPHABIT  0
#define DIGITBIT  1
#define PRINTBIT  2
#define SPACEBIT  3
#define XDIGITBIT 4

#define MASK(B) (1 << (B))

/*
** add 1 to char to allow index -1 (EOZ)
*/
#define testprop(c, p) (luai_ctype_[(c) + 1] & (p))

/*
** 'lalpha' (Lua alphabetic) and 'lalnum' (Lua alphanumeric) both include '_'
*/
#define lislalpha(c) testprop(c, MASK(ALPHABIT))
#define lislalnum(c) testprop(c, (MASK(ALPHABIT) | MASK(DIGITBIT)))
#define lisdigit(c)  testprop(c, MASK(DIGITBIT))
#define lisspace(c)  testprop(c, MASK(SPACEBIT))
#define lisprint(c)  testprop(c, MASK(PRINTBIT))
#define lisxdigit(c) testprop(c, MASK(XDIGITBIT))

/*
** In ASCII, this 'ltolower' is correct for alphabetic characters and
** for '.'. That is enough for Lua needs. ('check_exp' ensures that
** the character either is an upper-case letter or is unchanged by
** the transformation, which holds for lower-case letters and '.'.)
*/
#define ltolower(c)                                                     \
    check_exp(('A' <= (c) && (c) <= 'Z') || (c) == ((c) | ('A' ^ 'a')), \
              (c) | ('A' ^ 'a'))

/* one entry for each character and for -1 (EOZ) */
LUAI_DDEC(const lu_byte luai_ctype_[UCHAR_MAX + 2];)

#else /* }{ */

/*
** use standard C ctypes
*/

#include <ctype.h>

#define lislalpha(c) (isalpha(c) || (c) == '_')
#define lislalnum(c) (isalnum(c) || (c) == '_')
#define lisdigit(c)  (isdigit(c))
#define lisspace(c)  (isspace(c))
#define lisprint(c)  (isprint(c))
#define lisxdigit(c) (isxdigit(c))

#define ltolower(c) (tolower(c))

#endif /* } */

#endif
